1. Field of the Invention
The present invention relates to a backlight assembly and a liquid crystal display having the same, and more particularly, the present invention relates to a backlight assembly and a liquid crystal display having improved light efficiency and brightness uniformity.
2. Description of the Related Art
Recently, a flat panel display apparatus, such as a liquid crystal display (“LCD”), a plasma display panel (“PDP”), and an organic light emitting diode (“OLED”), has been developed in place of a cathode ray tube (“CRT”).
An LCD includes an LCD panel having a thin film transistor (“TFT”) substrate, a color filter substrate, and a liquid crystal layer interposed between the TFT substrate and the color filter substrate. Since the LCD panel does not emit light by itself, the LCD may further include a backlight unit disposed in a rear area of the LCD panel. The transmittance of the light from the backlight unit is adjusted according to an alignment of liquid crystal molecules within the liquid crystal layer. The LCD panel and the backlight unit are accommodated in a chassis.
The backlight unit may be classified into an edge type and a direct type according to a location of a light source within the backlight unit. The edge type has the light source at the side of a light guiding plate and is used for a relatively small-sized LCD such as a laptop and a desktop computer. The edge type generally has high light uniformity and a good endurance, and is suitable to make the LCD thin.
A point light source, such as a light emitting diode (“LED”), has recently been used for a light source for the edge type backlight unit. The point light source is disposed on a side of the light guiding plate, that is, along a light incident surface of the light guiding plate, and is disposed at regular intervals. Unlike a line light source such as a lamp, light from the point light source is not uniformly provided to the light incident surface of the light guiding plate. Therefore, brightness of the edge type backlight unit using a point light source becomes non-uniform since a portion of the light guiding plate corresponding to the point light source is bright and a space on the light guiding plate corresponding to between point light sources is dark. Furthermore, a large part of light from the point light source becomes total-reflected and therefore extinct and unusable by the LCD panel. Therefore, light efficiency may disadvantageously be low.